1. Field of the Invention
This invention relates to a method of producing a low-molecular luminous material dispersant, an apparatus for producing a low-molecular luminous material dispersant and a low-molecular luminous material dispersant
2. Description of the Related Art
As one of EL (Electroluminescence) materials emitting light with an electric field being applied, the organic EL materials that luminescence materials are organic materials are known. As for the organic EL materials, luminescence materials are classified mainly into high molecule organic EL materials made of a polymer-shaped molecule and low molecule organic EL materials (a fluorescent luminous material and a phosphorescent luminous material). Low molecule organic EL materials are widely used as a phosphorescent membrane on the organic EL display bases etc. because Low molecule organic EL materials have a long lifetime of luminescence and high luminescence efficiency in comparison with high molecule organic EL materials (see a Japanese Patent Laid-Open No. 2002-121606 bulletin).
A low-molecular organic EL material is deposited by evaporation on a substrate by an evaporation method to heat a material to vaporize in a vacuum atmosphere. However, when depositing by the evaporation method, it is difficult to deposit a luminescence film with a uniform film thickness on a large area substrate. Meanwhile, in order to solve such a problem, a method of depositing the low-molecular organic EL material on the substrate by utilizing an applying method to apply solvent in which the material is dissolved is considered. However, the low-molecular organic EL material is not dissolved in the solvent without change of a chemical structure thereof (solvent solubilization). Therefore, when using the solvent solubilization method, a characteristic such as luminescence efficiency and lifetime of luminescence of the low-molecular organic EL material is lost due to the change of the chemical structure.